A porous granular ammonium nitrate fuel oil explosive is an on-site mixed-loaded bulk explosive obtained by mixing porous granular ammonium nitrate and diesel according to the proportion of 94.5:5.5, has the characteristics of rich raw materials, simplicity in processing, low manufacturing cost, good fluxion property, safety in use, large gas energy and appropriate detonation velocity and is widely applied in open-pit mining blasting operations.
In spite of low cost, the porous granular ammonium nitrate fuel oil explosive is non-water-proof and non-moisture-proof, so it is suitable for regions with drought and little rain, and needs to perform moisture-proof treatment for construction in rainy seasons and mining areas with rich groundwater, as well as water-containing blast holes and moist blast holes; and furthermore, the relative volume energy and the weight energy are relatively low, so it is not particularly suitable for blasting hard rocks.
The porous granular ammonium nitrate fuel oil explosive is generally mixed by the on-site mixed loading truck for the porous granular ammonium nitrate fuel oil explosive and directly loaded into the blast hole, when a small amount of water is contained in the blast hole, one method is that, the blast hole is lined with a plastic bag, and then loaded with the explosive, but the method can not realize coupling loading; and another method is that, water in the blast hole is firstly drained, including blasting drainage, water pumping and the like, and then the explosive is loaded, but the method may enable the follow-up incoming water in the blast hole to dissolve ammonium nitrate and cause the failure of the explosive because the blast hole is connected with a nearby groundwater source.
An emulsion explosive has the characteristics of good waterproof performance, strong waterproof capability, large relative volume energy, high density and high detonation velocity, but the density-modifiable range is small, the explosion performance is stable between 1.05 and 1.35 g/cm3, and the emulsion explosive is suitable for blasting rocks above medium hardness; and the emulsion explosive has the shortcomings of high manufacturing cost, high density and high unit consumption of the explosive, the emulsion explosive needs to be loaded section by section when being packaged and can not realize coupling loading, and the on-site mixed-loaded emulsion explosive generally adopts an on-site mixed loading truck for emulsion explosives to realize the loading of the emulsion explosive.
In blasting construction of a mine, due to the influence of complex and changeable environmental conditions, including variable rock hardness conditions, presplitting blasting requirements, construction in rainy seasons, rock joints and other various conditions, if the existing on-site mixed-loaded ammonium nitrate fuel oil explosive or the emulsion explosive is adopted, it is very difficult to consider the blasting effect while keeping the unit consumption of the explosive unchanged.